Chuck key and support



March 3l, 1959 A. M. sToNER CHUCK KEY AND 'SUPPORT Filed Feb; 5, 1957nited States Patent() Jacobs Manufacturing Company, West Hartford,Conn., a corporation of New Jersey Application February 5, 1957-, SerialNo. 638,249

7 Claims. (Cl. 279-58) This invention relates 'to chucks, particularlyof the class "in which the jaws are tightened by manipulation of a keywhich is turned about an axis transverse to the chuck body. Theinvention is directed to a rotatable key assembly constructed andsupported in a novel manner for convenient manipulation.

An object of the invention is the 'provision of a key having twomanipulative portions, one having 'a Small 'radius for rapid turning andthe other having a larger radius or moment arm for greater leverage.

Another object is to reduce the manufacturing cost of a chuck keyassembly.

A further object is `to provide improved means for supporting the keyand permitting it to be moved quickly :finto and 'outof operativeposition. Other objects and features of the invention will appear ftherelclearly trom the following description taken in connection with theaccompanying drawings and appended claims.

lIn 'the accompanying drawings, which illustrate one `embodiment of thisinvention:

Fig. l isa longitudinal section of Aan internally geared chuck in-association with the rotatable key and its sup- I'porting means, theleft side 'of the igure showing the jaws 'raised and the right sideshowing the jaws lowered or collapsed;

Fig. 2 is a longitudinal section through the rotatable key 'of Fig. l;

-'fthe rotatable key, on la smaller scale than Figs. l, 2 and 3; -andFig. '5 isa plan View `of the rotatable key'holder on the "same scale asFig. .4.

In "the illustrative embodiment of invention a pinion 42 yis provided atits inner end with a series of longitudinally Vextending teeth 42:adapted 'to 'be inserted into a `radial lbore 43 in `the body 44 of achuck 4.5. The chuck, which 'will Ibe "described later, includes atacegear 46 vhaving lteeth which inesh with the teeth 42t 'on pinion 42. The.pinion 42 forms part 'of a rotatable key assembly confstructed fandsupported i-n fa. novel manner for convenient manipulation. A's shown inFig. i2, the pinion `has a "cylindrical body 47 coaxial with the toothedportion 42! and separated therefrom by an annular groove 48 having theshape of a half torus. The groove is adapted for the reception 'of `abrass :grommet 49 to be `described later. At its opposite end, thepinion 42 has a tapered extension 50 which has 'a press lit within acorrespondingly shaped `opening 'in a Yknob 51. AAdjacent the taperedextension 50,

the pinion hasra shoulder 52 in 'abutting engagement with The `knob has`a tapered periphery provided .'with tintes V53 enabling Ait to begrasped conveniently beltw'een tlhe thumb land -foref-nger of theoperator for rapidly ."tufrningthe-rotatable key assembly,including-.the pinion 42, when there is little resistance to rotation.The pinion body 47 has a diametrical hole 55 which receives, withPatented Mar. 31, 1959 d icc Va tight t, a wire handle or cross bar 56.The cross ba'r has a length considerably greater than the diameteroftheknob 51, and is adapted to be grasped between the operators fingers toenable him to turn the key assembly when the resistance to rotation ismore substantial. The knob 51 may be of metal formed by die casting, ormay be composed of plastic material. Since it transmits only arelatively small torque to the pinion, there is no difficulty inproviding a sufficiently secure connection between the knob and thepinion 42. The Wire handle prevents excessive torque from being appliedto the pinion teeth 42t and to the teeth on face gear 46 because it isdesigned to bend at torques considerably less than the breaking point ofthe teeth. The pinion 42 consists of an integral structure comprisingtoothed portion 42t, body 47 and extension 50. This part, like the otherparts of the rotatable key assembly, is inexpensive and easy to make. In'the manufacture of the pinion 42, the plain cylindrical diameter 47facilitates chucking and the pinion can be passed through the gearcutter work holding spindle for automatic loading.

In order to support the rotatable key assembly 42, 51, 56 in convenientposition for use, and to prevent the clisplacement or loss of the key,the grommet 49 is arranged to be supported by a flexible strap 57. Thestrap, which 'is shown unassembled in Figs. 4 and 5, is cut from a flatstrip, preferably made from oil-resisting synthetic rubber. At its lowerend, the strip 57 has an opening 58 whose normal unstressed diameter isslightly less than that of the toothed portion 42r of the pinion 42. Thebrass grommet 49, as seen in Figs. 2 and 3, has an annular groove ortorroidal recess "at lits outer periphery which snugly receives theapertured portion 58 of vthe strap. The grommet is convex on its insideto provide a swivel support on the pinion 42 adjacent the toothedportion 42t. As seen in Fig. 3, the grommet is in the form of a splitring. It is adapted to be expanded, slipped over the toothed portion42t, while in open condition, and then assembled within the annulargroove 48 by means of a squeezing or crimping action. To assemble thestrap with relation to the grommet, the area surrounding the hole 58 isstretched to the maximum di ameter of the tooth edges 42C and grommet 49to permit it to be passed thereover. Extending upward from 'theapertured portion 58, the strap 57 has a narrowpor'tion 59 above whichlies a body portion 61. The latter terminates in a head 62 having atransverse slit l63 cxtending between two holes 64. The perforatedportion 63, 64 may be stretched to provide a slot or opening ofsubstantial size. ln use, the body portion 61 is wrapped around asuitable support lsuch as the wire 65 (Fig. l) which delivers power tothe portable electric drill (not shown); the apertured lower end of thestrap, surrounding the hole 58 is folded and inserted through thestretched or opened slit 63, and the lower end 58 of the strapzis pulleduntil the narrow portion 59 and later a part of the body portion 61 havepassed through the slit 63 and the upper end of the strap 57 snuglyembraces the wire 65 as shown in Fig. l. The lower end 58 is then forcedinto position 011 the grommet 49 as described above, whereupon therotatable key assembly comprising manipulative knob 51 and pinion A42 iSSupported for movement into and out of working position at the `will ofthe operator. If desired, the strap 57 may be Vshifted along the lengthof the wire to any desired position and then frictionally locked to itsposition of `support on the wire. With this end in view, the holes 64karelso `dimensioned and spaced that the length of slit 63 Aadded t'othe combined diameter of two holes n64 is equal to the width 'of thebody portion l61. To -release the :strap for shifting along the Wire,vand the lock it -intadjusted position, the body 61 is respectivelypushed into, and pulled out of, the slotted head 62.

The chuck 45 comprises a nose piece 97 secured to Ythe lower end of thebody 44, a resilient collet 98 supported within the nose piece and athrust plug 100 resting atop the collet, the thrust plug having athreaded connection with a cylindrical extension 99 on the face gear 46.In order to permit vertical movement of the thrust plug 100 whilepreventing rotary movement, the plug is provided with a pair of tonguesor splines 101 extending outwar'l and slidably mounted within grooves102 on the inside wall of the chuck body 44. The face gear 46, with itsextension 99, is rotatable in the chuck body 44 but is prevented frommoving axially by a ball thrust bearing 103 resting on top of theextension 99 and a snap ring 104 supporting the bottom of the face gear46 and supported within an annular groove of the body member 44.

In operation, let it be assumed that the jaws 105 of the collet 98 arein the expanded condition as shown on the left side of Fig. l, that theoperator has inserted a work piece such as a drill bit (not shown)within the collet and that he desires to clamp the work piece by movingthe collet downward and inward toward the position shown onthe rightside of Fig. l. The nose piece 97, being firmly seated against the lowerend of the body 44 cannot move upward therein and therefore the only waythe operator can collapse the jaws is to bring the thrust plug 100downward. To this end, the operator first grasps the rotatable keyassembly by the knob 51 thereof and inserts the pinion 42 of said keythrough the radial bore 43. The pinion is supported for rotation aboutits individual axis by the engagement between the peripheral surface ofthe teeth 42t with the bore 43. The operator, still grasping the smalluted knob 51, 53, turns the key rapidly, thereby imparting rotation tothe face gear 46. The thrust plug 100, being constrained by the tongueand groove connection 101, 102 for axial movement only, moves downwardin response to the interengagement of the relatively rotating screwthreads provided on the face gear member 46, 99 and thrust plug 100respectively. As the jaws 105 of the collet 98 are pushed downward,their outer edges slide over the conical surface in the nose piece 97 toimpart to the jaws, by a camming action, an inward component of motion.Such motion is opposed by the resistance of the rubber body 106associated with the jaws. As the operator continues to turn the knob 51on the rotatable key 51, 56, 42, downward movement of the thrust plug100 meets with increased resistance from the rubber body 106 and Vfromthe frictional engagement between the edges of jaws 105 and the internalsurface of the nose piece 97. The resistance to such downward movementincreases abruptly as the jaws come into contact with the work piece(not shown). The effect of the resistance is to cause the face gearmember 46, 99 to react upward, but such upward thrust is sustainedeffectively by the raceway 103. At the same time, a reactive force isset up in the pinion 42 at the point of engagement of the teeth 42t withthe face gear 46. The entire force of such reaction is transmitted inatorsional direction through the pinion 42, back to the operator and doesnot have any tendency to disalign the pinion with the axis of itsbearing surface 43. The operator, upon feeling such increased resistanceto rotation releases the small diameter knob 51 and grasps theWire-handle 56 between his fingers, thereby increasing the effectivediameter or moment arm of the key assembly and gaining greater leverageto tighten the chuck to its final position. When this has beenaccomplished, as manifested by the tendency of the wire handle 56 toflex, the operator merely removes the rotatable key assembly 42, 51, 56and the chuck remains securely locked in tightened position by thefrictional engagement of the threads interposed between the face gear46, 99 and the thrust plug 100.

When the operator desires to release the work piece from the chuck, hereinserts the key 42 and reverses the direction of rotation thereof,resulting in upward movement of the thrust plug against a very lightresistance. Motion of the pinion 42 into and out of the chuck body 44occurs without any interference between the chuck key assembly and thesupporting means therefor, as the strap 57 is free to bend or ex.Rotation of the pinion 42 to tighten or loosen the chuck jaws likewiseis not obstructed by the support as the grommet 48 swivels freely aboutthe axis of the pinion. On the other hand, the supporting means,including the strap 57, holds the key assembly at all times in aposition within convenient reach of the operator.

What is claimed is:

1. A rotatable key for tightening and loosening the jaws of a chuckcomprising a pinion having teeth insertable into the chuck, a knobrigidly attached to the pinion and extending outward axially therefrom,the knob having a manipulative portion near the outer end of the key andadapted to be grasped between the operators thumb and forenger toinitially turn the key rapidly under relatively small torque resistance,the key having intermediate its ends a manipulative portion of largerdiameter adapted to be grasped by the operator to impart torque at arelatively slower rate but with increased leverage.

2. A key according to claim l, in which the pinion has an extension atits outer end adapted to tit within a recess at the inner end of theknob.

3. A key according to claim 2, in which the pinion has a body portionseparated from the toothed portion by an annular groove.

4. A key according to claim 3, in which a grommet is swivelly mounted onthe pinion and lies within the annular groove.

5. A key according to claim 4, in which the grommet consists of a splitring, said ring being convex on the inside and having side wallsabutting against the respective ends of the body portion and pinionportion.

6. A key according to claim 5, in which the grommet is provided with aperipheral recess and supports within said recess an apertured portionof a strap for supporting the key.

7. In a key operated chuck device, a rotatable key having a body portionand a pinion separated from the body portion by an annular groove, incombination with a key support, said key support comprising an elongatedtiat, exible strap, the upper end of the strap having a head providedwith a transverse slit, the lower end having a bore, a grommet supportedwithin said bore, said grommet being externally recessed and having amaximum diameter exceeding the normal diameter of the bore, whereby thebored portion of the strap must be stretched for attachment to orremoval from the grommet, said grommet being positioned within theannular groove and providing a swivel mounting for the chuck key, thebored portion of the strap being adapted to be folded and insertedthrough the slit at the head end, the lower and intermediated portionsof the strap being adapted to be pulled successively through the slit topermit the strap to be clasped at its upper end upon a fixed supportsuch as an electric wire.

References Cited in the tile of this patent UNITED STATES PATENTS

